exec-util,conf-files: skip non-executable files in execute_directories()

Fixes: #6787

src/udev/net/link-config.c

@@ -213,7 +213,7 @@ int link_config_load(link_config_ctx *ctx) {
         /* update timestamp */
         paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, true);
 
-        r = conf_files_list_strv(&files, ".link", NULL, link_dirs);
+        r = conf_files_list_strv(&files, ".link", NULL, 0, link_dirs);
         if (r < 0)
                 return log_error_errno(r, "failed to enumerate link files: %m");
 

src/udev/udev-rules.c

@@ -1533,7 +1533,7 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names) {
 
         udev_rules_check_timestamp(rules);
 
-        r = conf_files_list_strv(&files, ".rules", NULL, rules_dirs);
+        r = conf_files_list_strv(&files, ".rules", NULL, 0, rules_dirs);
         if (r < 0) {
                 log_error_errno(r, "failed to enumerate rules files: %m");
                 return udev_rules_unref(rules);

src/udev/udevadm-hwdb.c

@@ -627,7 +627,7 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
                 }
                 trie->nodes_count++;
 
-                err = conf_files_list_strv(&files, ".hwdb", root, conf_file_dirs);
+                err = conf_files_list_strv(&files, ".hwdb", root, 0, conf_file_dirs);
                 if (err < 0) {
                         log_error_errno(err, "failed to enumerate hwdb files: %m");
                         rc = EXIT_FAILURE;